Increase in gloss or sheen of paint film when subjected to rubbing, scrubbing or having an object brush up against it.

Possible Cause:
Use of flat paint in highly trafficked areas where a higher sheen level would be advisable.
Frequent washing and spot cleaning.
Objects (furniture, for example) rubbing against the walls.
Use of lower grades of paint with poor stain and scrub resistance (See poor stain resistance and poor scrub resistance).

Solution:
Paint, with a top quality latex paint, heavy wear areas that require regular cleaning . Generally, in high traffic areas, choose a semi-gloss or gloss paint rather than a flat sheen level. Follow directions to clean painted surfaces: use a soft cloth or sponge and a mild, nonabrasive cleanser followed by a thorough rinse.